Fixed bug where an exception was thrown when removing an editor after opening the context menu multiple times.
Worked more on skin variables.
Fixed some issues with UI states.
Worked on skins some more.
Merge pull request #248 from dosercz/master

Fixed typo in unordered char list regexp
Fixed bug #6347
Fixed issue with callback on alert boxes.
Fixed menubar and checkbox skin issues.
Separated up button border and fixed some variable issues in default skin.
Renamed all skin variables to a more strict naming convention.
Fixed bug where paste as plain text on Gecko would add extra BR elements when pasting paragraphs.
Fixed skin variables for grid items.
Fixed bug where editors wouldn't initialize some times due to event logic not working correctly.
Fixed two remove editor related issues.
Fixed bug where closing a dialog with an opened listbox would cause errors if new dialogs where opened.
Fixed a bug with pre elements in searchreplace/spellchecker logic.
Fixed some issues with importcss plugin.
Added some more skin variables.
Fixed bug where layout managers wouldn't handle subpixel values properly.
Fixed issue with measure of label box.